Radio receiving system



1,702,445 L NPQN RADIO BECEIVING SYSTBI Filed April 2, 1 2

INVENTOR Verna/7 0. Landon v ATTORNEY Patented Feb. 19, 1929.

UNITED STATES PATENT OFFICE.

VERNON D. LANDON, OF EAST PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTING- HOUSE ELECTRIC & MANUFACTURING VANIA. v

Application filed April 2,

My invention relates to systems for the receptionof radio signals.

One object of my invention is to provide a more convenient and more eflicient means for the reception of radiofrequency signal energy.

Another object of' my invention is to provide means comprising a plurality of triode thermionic discharge devices in connection with a radio receptor circuit, whereby reinvention will be apparent from the following description when read in connection with the accompanying drawing, wherein:

The single figureis a diagrammatic sketch of a radio receiving apparatus comprising my invention.

vIn the drawing, a radio receiving system comprises a radio receiving aerial 1, a series tuning condenser 2, a series tuningvinductance 3 and a ground 4 connectedthereto. A

triode 5 has anode, cathode and grid el'ec-. trodes and electric current supply sources are connected thereto. Acoil 10 in inductive relation to inductance 3, is connected in the plate circuit of triode 5. i The-grid electrode of triode 5 is connected to the conductor between the'condenser 2 and the inductance 3,

and the cathode of triode 5 is connected to the conductor between the inductance 3 and the ground 4. By this means, the triode 5is caused to furnish regenerating energy to the radio receptor circuit.

A triode 6, which is also provided, has-its electrodes connected to, the same current sources which furnish current for the triode 5, by suitable connections and resistance control means. The gridof triode 6 is connected to the same lead as is the grid of triode 5. A radio-frequency transformer 7*is provided, having a number of coils. Coil .8- is the primary winding of'theztransformer and COMPANY, A CORPORATION OF PENNSYL- RADIO RECEIVING SYSTEM.

1924. Serial No. 703,669.

is connected between the anode of triode 6 12 which is shunted by a condenser 13.

The cathodes of triodes 14 and 15 are coni nected together and through a rheostatic control means to the previously mentioned supply of cathode heating current. Likewise, the grids of triodes l4 and 15are connected together, and to one terminal of the secondary winding 12 of amplifier transformer 7.

The transformer 7 is equipped with 'a fourth coil 16 which is connected between the anode of triode 14 and the source of plate current, as indicated in the sketch.

A second amplifying transformer. 17 is similar in constructlon to transformer-7, having four. coils similar to the coils of trans- 1 former 7. Coil 18, which is the primary winding of transformer 17 is connected be- 1 tween vthe anode of triode 15 and the source of plate current. Asecond coil 19, also in inductive relation to coil 18, is connected be tween the coil 18 and a condenser 21. The

second terminal of condenser 21 is connected to the grid of triode 15. The coil 19 and the condenser 21, as before,,serve as a reversed feed-back means whereby triode 14 is prevented from sustaining itself in oscillation. Coil 22 is the'secondary of transformer 17. It is shuntedvby a condenser 23 in a manner similar to the shunting of coil 12 .by con denser 13. y

The cathode of'a detector triode 24 is connected to the source of cathodeheating current. The grid of triode 24 is connected to a grid leak and a grid condenser combination 25, the other terminal of which is connected to aterminal of'coil 22; The second terminal of coil 22 is connected to the cathodeof triode 24. I The anode of triode 24is connected to the fourth coil 26 of transformer 17 The other terminal of coil 26 is connected to sig nal receivers 27 from which the circuit is continued by a conductor to the source of plate nected between the second lead from coil 26' and the cathode lead of triode 2a. The condenser 28 serves as a by-pass for rad1o-i'irequency energy in the plate circuit. of triode.

connected impedances when the constants of the impedances are adjusted to bring the circuit into resonance with the arriving signals. Potential variations corresponding to the re ceiving signals are then impressed upon the grids o'l" triodes 5 and 6 in the customary manner.

The triode 5, by virtue of the inductive coupling between. its plate coil 10 and the inductance 3 in the aerial circuit, furnishes re-' generative energy to increase the amplitude of the oscillatory current produced in theantenna and its connected resonant circuit. Energy from the same signals is likewiseimpressed upon the grid of triode 6, which energy is increased in amplitude by the regenerative action of the triode 5 and'the connected coil 10.

The triode 6 impresses, through coil 8' in its anode circuit, amplified oscillatory energy upon the secondary coil 12 of transformer 7'. The presence of coil 9 and condenser 11, which together constitute a reversed feedback, prevents the triode 6 from oscillating or tending to oscillate, thereby causing the triode 6 to have a purely repeating and amplitying action.

Energy from coil 12 is impressed upon the grids of triodes 14 and 15. The presence of coil 16 in inductive relation tocoil 12, which is connected in the anode circuit of'triode 14, produces a regenerative action upon the energy received by coil 12, thereby increasing the amplitude of the oscillations impressed upon the grid oftriode 15.

The presence of coil 18 connected in the anode circuit of triode 15 causes the trans for of energy to coil 22 through transformer- 17. As in the transformer 7, a reversed feed baclr is provided, coil 19. and condenser 21 being the means for producing the reversed feedvback which prevents the triode 15 from tending to. oscillate. The energy transferred from coil 18 to coil 22 is impressed upon the grid oftriode 24L by way of the grid leak and grid condenser 25.

The presence of coil 26 in the. anode circuit of the triode 2a gives a regenerative action from triode 24 as well thereby allowing-maiz imum amplification and the production of maximum signal strength in receivers 27' which are connected inthe anode circuit of triode 24.

By this means I am enabled to'produce a radio receiving system in which the functions of regeneration and the functions of amplifie ration are performed by separate triodes,

thereby obtaining greater efiiciency in amplificat-ion and greater accuracy of repetition.

While I have shown only one embodiment of my invention in the, accompanying drawings, it is. capable of various, changes and modifications without departing from the spirit; thereotand it is desired, therefore, that only such. limitations shall be imposed thereonasare indicated the prior art or in the appended claims.

I claim as my invention:

1. A regenerative radio receiving system comprising a radio-frequency responsive circuit, and connected amplifying, detecting and signal reproducing means, said means comprising stages, said stages being arranged cuit, and connected amplifying, detecting and signal reproducing means, saidmeans comprising stages, said stages being arranged in cascade and the cascade couplings'be-ing only between the. stages, each of said stagesv comprising a plurality of triodes and circuits, one of said-triodes and its circuits constituting a regenerative device, another of said triodesan-d its circuits constituting a re: peatlng device and said repeating device curcuitscomprising a reversed feed-back circuit.

3 A radio receiving system comprising- 1n comblnatlon a trlode having a feed-back circuit, a. second triode having a reversed feedback-circuit and a direct, small-impe dance connection betweenthe grids of said triodeswhereby said grids are always at the same potential;

4L. A regenerative radio receiving system' comprising in combination, a triode having a feed-baclr'cireuit, a second triode havlng a reverse feedback circuit, and interlinlringand cooperative circuits, said circuitsincl'ud ing means whereby both the received signal and theu'csultof feedback are impressed on I the grid of the second triode and thereby causing said triodes to cooperate in the am plification of signals.

5. In a radio device, a pair of vacuum tubes having their grids directlyv and immediately connected, 'means for rendering one of said tubes regenerative, and means for preventing regeneration. of the other tube.

6. In a radio receiving system, a plurality of amplifying stages, each stage comprising a plurality of vacuum tubes, direct (30111190.

tions between thegrids oithe tubes of each stage, means: whereby at least one of the tubes;

of each stage may berendered regenerative, and means whereby at least one of the other tubes of each stage is prevented from regenerating. o

7. In a radio receiving system a pair of thermionic devices having a common input circuit, each thermionic device having an individual output circuit, means for coupling the output circuit of one of said devices to said common input circuit, in a sense to cause regeneration, and means for coupling the output circuit of the other of said devices to said common input circuit in a sense to 0 pose regeneration of oscillations in said lastmentioned device.

In testimony whereof, I have hereunto subscribed my name this 27th day of March, 1924. i

VERNON D. LANDON. 

